Bobbin case for sewing-machine shuttles



April 1 1924.

E. J. THOMSON BOBBIN'CASE FOR SEWING MACHINE SHUTTLES Filed May 29, 1923 55167 2M wzM" Patented Apr. 'i, 1924.

users are PATET OFFICE.

EDWARD J. THOMSON, G13 QUINCY, MASSACHUSETTS, ASSIG-NOR '10 SUMMIT THREAD COMPANY, OF "EAST HAMPTON, CONNECTICUT, A GORPORATION OF MAINE.

BOBBIN CASE FOR SEWING-MACHINE SHUTTLES.

Application filed May 29,

To all whom it may concern Be it known that I, EDWARD J. THOMSON, a citizen oi? the United States, residing at Quincy, in the county of Norfolk and State of Massachusetts, have invented new and useful Improvements in Bobbin Cases for tiewing-lvlachine Shuttles, of which the following is a specification.

This invention relates to the bobbin case element of a shuttle, havinga central post on which a bobbin is adapted to rotate, and has for its object to provide an improved construction whereby a ready-wound bobbin in the bobbin case may be confined against undesirably loose and tree rotation on the post, and at the same time permitted to rotate without excessive frictional resistance.

l attain this object by the improved construotion hereinafter described and claimed.

Gt the accompanying drawings forming a part of this specification,-

Figure l is a perspective view of a bobbin case embodying the invention.

Figure 2 is a sectional view of the same.

Figure 3 is a top plan view of the outer disk hereinafter described.

Figure 4 is a section on line 4-4 of Figure 3.

Figure 5 is a perspective view of the stop collar shown by Figure 2.

The same reference characters indicate the same parts in all the figures.

In the drawings, 12 represents the closed inner end or bottom, and 13 the annular wall of a bobbin case which is open at its outer end.

The case is provided with a central tubular post 10, on which a ready-wound bobbin, composed of a core 14 and a thread winding 15, is rotatable.

To the post is pivoted at 16 a latch 17, adapted, as usual, to be yieldingly held in position to either confine the bobbin, as shown by full lines, or to release the bobbin, as shown by dotted lines (Figure 2), means commonly employed for this purpose being shown by Figure 2, including a bevel-faced spring-pressed plunger 18 in the post, and a cam head 19 on the inner end of the latch.

Surrounding and movable on the post is a fiat annular inner disk 20, adjacent to the inner end of the case, and adapted to bear on the inner end of the bobbin. Said disk is pressed outward by a spring 21. 22 rep- 1923. Serial No. 642,344.

resents a fiat annular outer disk, also surrounding and movable on the post, and

adapted to bear on the outer end of the bobbin. The invention resides in this disk.

Said outer disk is provided with an annular hub having a sliding fit and a relatively' wide bearing on the post 10, whereby atendency of the disk to bind on the post in consequence of an unbalanced pressure on the disk, is reduced to a minimum. By unbalanced pressure I mean a greater pres sure on the diskat one side of the post than elsewhere, tending to slightly tip the disk and cause the wall or" its central opening to bind on the post.

The hub is composed of an inwardly projecting inner portion 23 and an outwardly projecting outer portion 24, hereinafter called an annular rib. The inner portion 23, which is preferably beveled as shown, is adapted to enter and frictionally engage the bobbin core 14. The annular rib 24 is adapted to bear on the inner portion of the latch 17, when the latter is in its bobbinconfining position, and prevent contact between the outer portion of the latch and the outer disk 24, between the rib and the mar- I gin of the disk, as shown by Figure 2.

The described parts are adapted to be assembled by placing the spring 21 in the case, placing the inner disk 20 on the spring, applying to the post 10 a cut resilient stop sleeve 26, whichfrictionally engages the post and is adjustable thereon to limit the outward movement of the disk 20 by the spring, and engaging the outer disk 22 with the bobbin. During this operation the latch 17 is in its releasing position, as shown by dotted lines. The latch is then moved to its confining position, and its inner portion comes to a bearing on the annular rib .24 of the outer disk 22.

The spring 21 presses the disks and the bobbin outward as far as the latch permits, and causes the contact of the latch with the rib to frictionally retard the rotation of the bobbin.

The outward projection of the rib 24 from the outer side of the outer disk 22, preventing contact of the outer side of the disk surrounding the rib with the latch, limits the bearing of the outer disk on the latch to the raised central portion formed by the rib, the marginal portion of the disk being out or. contact with the latch, so that the pressure is not unbalanced to the ex- I tent that it would be if the latch contacted with the marginal portion of the disk. The bobbin is therefore adapted to rotate evenly and with only sufficient frictional resilience to prevent it from rotating faster than required by the call of the thread unwound therefrom.

I prefer to provide the outer disk with sight openings permitting inspection of the thread winding 15, so that an operator may ascertain the quantity of thread Without removing the outer disk.

I claim: 7 V

A bobbin case closed at one end and open at the other end, having a tubular central post provided with a latch pivoted in the post; means for yieldingly holding the latch in position to either confine or release a bobbin in the case; a fiat annular inner disk adjacent to the closed end of the case and surrounding and movable on the post, and adapted to bear on the inner end of a bobbin in the case; a spring yieldingly pressing the inner disk toward the open end of the case; and a flat annular outer disk, also surrounding and movable on the post, and adapted to bear on the outer end of said bobbin; the said outer disk being provided with an annular hub having a sliding fit and a relatively wide bearing on the post, to oppose tipping of the outer disk on the post, said hub including an in wardly projecting inner portion adapted to enter the core of a ready wound bobbin, and an outwardly projecting outer portion constituting an annular rib adapted to bear on the inner portion of said latch when the latter is in a confining position, and prevent contact between the outer portion of the latch and the outer disk, the arrangement being such that the said disks and a bobbin interposed therebetween are pressed outward by the spring, to cause a frictional bearing of the outer disk on the latch, the said rib being the only portion of the outer disk which contacts with the latch, so that said bearing is limited to the central portion of the outer disk, the marginal portion of the disk being out of contact with the latch.

In testimony whereof I have affixed my signature. 7

EDWARD J. THOMSON. 

